Motor control system

Claim 2

A motor control system comprising: a rotor; a plurality of field windings connected to a relatively low frequency power source; rotatable magnetic flux producing means mechanically connected to said rotor; a plurality of saturable reactors adjacent said magnetic flux producing means; means for supplying a high frequency signal to said saturable reactors; a plurality of silicon-controlled rectifier switching means connected to said field windings, respectively, for controlling current flowing through said field windings for intervals of time corresponding intervals that said high frequency signal is derived from the respective ones of said saturable reactors; control means to produce a speed error signal; and means for modulating, in response to said speed error signal derived from said control means, the duration of time said high frequency signal is supplied to said switching means.

Claim 3

A motor control system according to claim 1 wherein said modulating means comprises a magnetic yoke and an additional saturable reactor opposite said magnetic yoke.

Claim 4

A motor control system according to claim 2 wherein said magnetic yoke for said modulating means comprises: a biasing coil to receive an alternating signal, and a control coil to receive said control signal from said control means; and said additional saturable reactor comprises: a saturable core, a primary coil wound on said saturable core to receive a high frequency signal from said means for producing a high frequency signal, and means for transmitting the output of said additional saturable reactor to said plurality of saturable reactors.

Claim 5

A motor control system according to claim 3 comprising said high frequency signal producing source, and means connecting said source to said primary coil.

Claim 6

A motor control system according to claim 2 wherein said additional saturable reactor comprises a transformer comprising a saturable core.

Claim 7

A motor control system according to claim 2 wherein said magnetic yoke for said modulating means comprises a biasing coil to receive an alternating current having a phase differing by a predetermined angle from the phase of a voltage to be supplied to said field windings, and a control coil to receive said control signal from said control means.

Claim 8

A motor control system according to claim 1 which further comprises magnetic bias means opposite said plurality of saturable reactors to apply a bias magnetic field to each of said plurality of saturable reactors.

Claim 9

A motor control system according to claim 1 wherein each of said saturable reactors includes a magnetic core and a biasing coil wound around said magnetic core to receive a direct current from a power source connected to said biasing coil.

Claim 10

A motor control system according to claim 8 comprising: a direct current source; and means to connect said source to said biasing coil in either polarity to produce a biasing magnetic field of selected polarity.

Claim 11

A motor control system according to claim 1 which further comprises; a detector for detecting the roTating speed of said rotor; and comparing means for comparing the output of said detector with a reference value to produce an error signal to be supplied to said control means.

Claim 12

A motor control system according to claim 10 wherein said control means comprises a diode bridge, whereby the absolute value of said error signal is supplied to said modulating means as a control signal.

Claim 13

A motor control system according to claim 1 wherein said plurality of saturable reactors comprises a plurality of transformers, each including a saturable core.

Claim 14

A motor control system comprising: a rotor; a plurality of field windings connected to a relatively low frequency power source for rotating said rotor; a magnetic flux producing means mechanically connected to said rotor; a plurality of saturable reactors adjacent the path of rotation of said magnetic flux producing means; means supplying a high frequency signal to said saturable reactors; a plurality of silicon-controlled rectifier switching means connected to said respective field windings for controlling current through said field windings corresponding to an output derived from a respective one of said saturable reactors; magnet means for magnetically biasing each of said saturable reactors; and means for changing over said magnetic field produced by said magnet means from one polarity to the opposite polarity.

Claim 15

A motor control system comprising: a rotor; a plurality of field windings connected to a relatively low frequency power source for rotating said rotor; a magnetic flux producing means mechanically connected to said rotor; a plurality of saturable reactors adjacent the path of rotation of said magnetic flux producing means; means supplying a high frequency signal to said saturable reactors; a plurality of silicon-controlled rectifier switching means connected to said respective field windings for controlling current through said field windings corresponding to an output derived from a respective one of said saturable reactors; magnet means for magnetically biasing each of said saturable reactors; and means for changing over said magnetic field produced by said magnet means from one polarity to the opposite polarity.

Claim 16

A motor control system according to claim 13 wherein said magnet means comprises; a magnetic yoke; and a biasing coil wound around said magnetic yoke.

Claim 17

A motor control system according to claim 13 wherein said saturable reactors comprise; saturable cores; a primary winding wound around each of said saturable cores to receive said high frequency signal; and a secondary winding wound around said saturable cores and connected to a respective one of said switching means.

Claim 18

A motor control system comprising a motor comprising a rotor and stator; a relatively low frequency alternating power source for supplying alternating power to said motor; silicon-controlled rectifier switching means connected to said power source for controlling current flowing through said motor; a comparison circuit; a reference signal source connected to said comparison circuit; means connected to said comparison circuit and operable for deriving a voltage corresponding to the speed of said motor; means for producing a second current having a polarity determined by said derived voltage; a saturable reactor having a coil to receive a high frequency signal and an output means for deriving output signals therefrom, said output means being connected to said switching means to actuate said switching means in response to a saturable condition of said saturable reactor; magnet means to receive said second current for producing magnetic flux and to supply said magnetic flux to said saturable reactor; and a control means provided at said magnet means for controlling the magnetic flux produced by said magnet means.

Claim 19

A motor control system comprising a motor comprising a rotor and stator; a relatively low frequency alternating power source for supplying alternating power to said motor; silicon-controlled rectifier switching means connected to said power source for controlling current flowing through said motor; a comparison circuit; a reference signal source connected to said comparison circuit; means connected to said comparison circuit and operable for deriving a voltage corresponding to the speed of said motor; means for producing a second current having a polarity determined by said derived voltage; a saturable reactor having a coil to receive a high frequency signal and an output means for deriving output signals therefrom, said output means being connected to said switching means to actuate said switching means in response to a saturable condition of said saturable reactor; magnet means to receive said second current for producing magnetic flux and to supply said magnetic flux to said saturable reactor; and a control means provided at said magnet means for controlling the magnetic flux produced by said magnet means.

Claim 20

A motor control system according to claim 16 wherein said saturable reactor comprises; a saturable transformer having a saturable core; a coil wound around said saturable core to receive the high frequency signal supplied from a high frequency signal producing source; and an output coil wound around said saturable core for supplying an output of said saturable reactor to said switching means.

Claim 21

A motor control system according to claim 16 wherein said magnet means comprises: a magnetic yoke and a coil wound around said magnetic yoke to receive said current; and a control coil wound around said magnetic yoke to receive a control direct current from said control means.